The power plant voltage/reactive power regulator with an adaptive control solution

The paper deals with the theoretical study and simulation results of adaptive control solutions applied to the grid voltage and reactive power regulation, with particular reference to the Italian transmission network multilevel control system. These three levels hierarchical control system operates at its lowest level by a specific power plant voltage/reactive power regulator named REPORT. The paper describes more precisely the REPORT conventional control scheme and regulation laws (generator reactive power control loop and power plant high side voltage control loop), as well as their possible dynamic performances improvement through a timely control parameters adaptation, depending on the interconnected network variations synthesized by the external reactance parameter change. The aim of the paper is to analyze, by simulations carried out through Matlab-Simulink, an "indirect adaptive control" strategy, based on a "discontinuous identification", applied to both the reactive power control and high side voltage regulation. The significant advantages achievable from such a strategy, in terms of increased stability and reduced dynamic interaction among the concurrent and overlapped control loops at both the generator and power plant levels, are also shown.